Throat plate for sewing machines



y 970 G. HAGEMEYER 3,513,795

THROAT PLATE FOR SEWING MACHJiNES Filed Oct. 1, 1968 2 Sheets-Sheet 1 INVENTbR MWfi/AP l/Mmwm M J. A4444 May 26, 1970 G. HAGEMEYER THROAT PLATE FOR SEWING MACHINES 2 Sheets-Sheet 2 Fig.

IINVENTOR United States Patent 3,513,795 THROAT PLATE FOR SEWING MACHINES Gunther Hagemeyer, Lemgo, Germany, assignor to Kochs Adlernahmaschiuen Werke AG, Bielefeld, Germany Filed Oct. 1, 1968, Ser. No. 764,205 Claims priority, application Germany, Mar. 12, 1968, 1,660,928 Int. Cl. Db 51/00 US. Cl. 112-260 6 Claims ABSTRACT OF THE DISCLOSURE A throat plate for sewing machines having an inset surmounting the upper face of the throat plate and a stitch hole for the needle. The inset is tiltably arranged within the throat plate. This throat plate especially suitable for pattern-controlled sewing devices in which the workpieces to be sewn are clamped between stitching templates having slots of a predetermined contour, formed in the upper and the lower plates for receiving the throat plate inset in the lower plate, and a liftable workpiece press pad in the upper plate. This movable throat plate inset makes it possible to avoid lifting of the templates above the throat plate inset for the purpose of removing the templates out of the area of stitch-forming after sewmg.

BACKGROUND OF THE INVENTION This invention is in the field of US. Patent Office classification Class 1l2-260 entitled Sewing Elements- Frames, Work Supports."

This invention relates to a throat plate for sewing machines which has an inset surmounting the upper face of the throat plate and which is provided with a stitch hole.

There are already known throat plates for sewing machines which are provided with a throat plate inset surmounting the upper face of the throat plate, and which are provided with a stitch hole for the vertically displaceable needle.

Such a throat plate inset is necessary for workpiece clamping frames having a lower plate disposed on the throat plate and an upper clamping plate in swivel connection with the lower plate, for clamping workpieces to be sewn between these.

In this case, the throat plate inset overtopping the upper face of the throat plate eliminates the difference in height between the upper face of the throat plate and the lower plate of the workpiece clamping frame, so that the edges of workpiece layers projecting from the clamping frame rest on the throat plate inset without deflection.

Such a throat plate is disclosed in British Pat. 600,039, published July 4, 1962.

In this patent there are shown superposed plates forming a stitching template, between which are interposed layers of material, and in which lower plate is formed a slot of a predetermined contour for engaging with a throat plate inset overtopping the upper face of the throat plate. In order to remove the template from the sewing machine, it is necessary to lift the template above the throat plate inset.

Whereas it is relatively simple to remove from or insert in small-sized stitching template, e.g. for pocket flaps, the sewing device in this manner, set in difficulties when using a workpiece carrying plate of larger dimensions, e.g. for sewing pockets on clothes. Therefore it is necessary to pivot the relatively heavy workpiece carrying plate for swinging it out of the sewing device. The heavy workpiece carrier plate must be lifted above the throat plate inset overtopping the throat plate, to bring it out of the 7 ice slot-shaped clearance in the workpiece carrier plate. For this purpose there is provided a controlled mechanism for lifting the workpiece carrier plate, depending on position of the needle, which is relatively intricate.

It is an object of this invention to provide a throat plate having an inset provided with a stitch hole and surmounting the upper face of the throat plate, which makes it possible to lift the workpiece carrier plate above the inset for swinging it away from the sewing machine after or before sewing.

A further object of this invention is to provide a throat plate of the above character which can be used in sewing machines installed in pattern-controlled sewing devices.

It is a further object of this invention to provide a throat plate of the above character which is adapted for installation in existing sewing machines without difficulty.

A still further object of this invention is to provide a throat plate of the above character which is simple in design and inexpensive in production.

SUMMARY According to the present invention these objects are attained essentially by a throat plate having a throat plate inset. which is movably arranged within the throat plate between two positions of the axis of the stitch hole. This throat plate inset may be tiltably arranged within the throat plate provided with an opening for receiving that part of the inset surmounting the upper face of the throat plate, when the sewing machine is stopped and the needle is out of the stitch hole.

Other and more specific objects and features of the invention will be apparent from the following description of the preferred embodiment, when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a throat plate with a tiltable throat plate inset and its operating means in a perspective partial view of a sewing machine, partly sectional, along the line I-I of FIG. 3;

FIG. 2 shows an enlarger partial section, taken along the line IIII of FIG. 3, and

FIG. 3 an essentially schematic top plan view of a sewing device with a sewing machine, in which the throat plate according to the invention is included.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the throat plate 1 which is inserted and secured in the bedplate 2 of a sewing machine 3, there is provided a throat plate inset 5 within an opening 4. This throat plate inset 5 surmounting the upper face of the throat plate 1 during the operating position of the sewing machine, is provided with a stitch hole 6 (FIG. 2) for the passage of the needle 7, and with shaft parts 8, 8' on both sides (FIG. 1), extending square with the longitudinal axis of the stitch hole 6. These shaft parts 8, 8' are pivoted in bearings 10, located in the bottom surface of the throat plate 1 and have a recess 9 in the throat plate 1 and two bearing caps 10 which are screwed to it by means of screw 11. The end 8' of the shaft 8, 8 is provided with a bending 12 extending rectangularly to the stitch hole 6. This bending 12 has a bevelling 13 for turning the throat plate inset 5 out of a position within the opening 4 (FIG. 1) into the operating position (FIG. 2).

In the bedplate 2 there is pivoted an operating shaft 14, one end of which is provided with an angular part 15, in effective connection with the bending 12. The other end 14 of the operating shaft 14 protrudes out of the bedplate 2 and carries an actuating lever 16. This is provided with a slit 17 and clamped to the end '14 of the shaft 14 by means of a clamping screw 18.

A supporting member is secured by screws 21. It carries an air cylinder 22, the piston rod 23 of which extends into a recess 24 of the actuation lever 16. A follower pin 25 is inserted in the piston rod 23 and enters the slits 26 in the actuating lever 16.

A sewing machine 3, provided with the above described throat plate 1, can be used in a pattern-controlled sewing device, as shown in FIG. 3. The sewing machine 3 is fixedly mounted on a carrier 27, at the jib 28 of which is pivoted a swinging lever 29. At the free end of the swinging lever 29 there is pivoted a workpiece carrier 30, which is displaceable in a horizontal plane on the bedplate 2 of the sewing machine 3. The carrier is provided with a workpiece clamping plate 31 which can be lifted about the bearings 32, where it is outside the area of the throat plate 1. Its function is to press the workpiece 33 lying on the workpiece carrier plate 30, and a workpiece cut 34, eg a pocket cut, disposed on the workpiece carrier plate 30.

In the workpiece carrier plate there is provided a slot 35 corresponding to the forms of seam to be sewn, for engaging with the throat plate inset 5. On this throat cut 34 are under slight pressure of a liftable workpiece cut 34 are under slight pressure of a liftable workpiece presser pad 36 on plate inset 5. A slot 37 for engaging with the workpiece press pad 36, corresponding to the form of the seam to be sewn, is provided in the workpiece clamping plate 31.

Before the needle 7 comes down to form a seam, starting at A (FIG. 3), a rotary motion caused by means of the air cylinder 22 (FIG. 1), will be translated to the shaft 8, 8 by means of the actuating lever 16, the operating shaft 14 and its angular part 15. The throat plate inset 5 connected with the shaft 8, 8', will be swung out of its rest position within the opening 4 into the operating position, shown in FIG. 2. After termination of the seam at B, the sewing machine 3 comes to rest with its needle being in high position and the workpiece press pad 36 in a raised position. At the same time the air cylinder 22 is vented by a device (not shown), controlled in dependence of the position of the needle 7.

The throat plate inset 5 will be shifted into the opening 4 of the throat plate 1 by an edge 38 of the slot 35, before swinging the workpiece carrier plate 30 out of the area of the sewing machine 3, for removing the workpiece 33 with the workpiece cut 34 sewn on it.

Owing to the shifting of the throat plate inset 5 into the clearance 4, the workpiece carrier plate 30 can be moved above the throat plate 1 without lifting it above the inset 5, which would be necessary if it were secured to the throat plate 1.

It will be understood that the present invenion is not limited to the exact details of the described construction and that modifications may be made in many respects without departing from the main principles of the invention.

I claim:

1. In a throat plate for sewing machines having a bedplate and a needle, an inset surmounting the upper face of the throat plate and provided with a stitch hole for a needle, means tiltably arranging said throat plate inset within said throat plate between two positions of the axis of said stitch hole, one a vertical upright or operative position and a horizontal or inoperative position.

2. A throat plate as claimed in claim 1, wherein said means includes comprising an opening for reeciving the part of said inset surmounting the upper face of said throat plate, when the sewing machine is stopped and the needle is out of said stitch hole.

3. In a throat plate as claimed in claim 1, wherein said means include bearings arranged in the bottom surface of said throat plate, shaft running at a right angle to the longitudinal axis of the stitch hole and pivoted in said bearings, and a bending on one end of said shaft running rectangular with the axis of said stitch hole, for operating said shaft.

4. In a throat plate for sewing machines having a bedplate and a needle, an inset surmounting the upper face of the throat plate and provided with a stitch hole for said needle, said throat plate inset being tiltably arranged within said throat plate, an opening in said throat plate for receiving the part of said inset surmounting the upper face of said throat plate, when the sewing machine is stopped and the needle is out of said stitch hole, bearings arranged in the bottom surface of said throat plate, said throat plate inset further provided with a shaft running at a right angle to the longitudinal axis of the stitch hole and pivoted in said bearings, one end of said shaft being provided with a bending extending at a right angle to said stitch hole, an operating shaft pivoted in the bedplate of said sewing machine and provided with an angular part at its one end cooperating with said bending of said shaft carrying said throat plate inset, an actuating lever secured to the other end of said operating shaft and protruding from said bedplate of said sewing machine, and driving means for actuating said throat plate inset.

5. A throat plate as claimed in claim 4, wherein said driving means for actuating said throat plate inset is an air cylinder controlled as a function of the position of said needle.

6. In an automatic sewing machine having a bedplate and a needle for sewing on workpiece cuts upon workpieces, a carrier having a jib, a stationary sewing machine mounted upon said carrier, a swinging lever pivoted on said jib, a workpiece carrier plate on said swinging lever and a workpiece clamping plate for clamping a workpiece between it and said workpiece carrier plate, said workpiece carrier plate and said workpiece clamping plate being provided with slots, and a workpiece press pad engaging said slot in said workpiece clamping plate, a throat plate inset in the throat plate of said sewing machine, said throat plate inset being provided with a stitch hole and surmounting the upper face of said throat plate and engaging said slot in said slot in said workpiece carrier plate, said throat plate inset being tiltably arranged within said throat plate, an opening in said throat plate for receiving the part of said inset surmounting the upper face of said throat plate when said sewing machine is stopped and the needle is out of said stitch hole, bearings arranged in the bottom surface of said throat plate, said throat plate inset further provided with a shaft extending at a right angle to the longitudinal axis of said stitch hole and pivoted in said bearings, one end of said shaft being provided with a bending extending at a right angle to said stitch hole, an operating shaft pivoted in the bedplate of said sewing machine and provided with an angular part at its one end cooperating with said bending of said shaft carrying said throat plate inset, an actuating lever secured to the other end of said operating shaft extending from said bedplate of said sewing machine, and a driving means for actuating said throat plate inset in dependence on the position of said needle.

References Cited UNITED STATES PATENTS 735,477 8/1903 Douglas 11226O MERVIN STEIN, Primary Examiner G. H. KRIZMANICH, Assistant Examiner 

